Coated core and method of and apparatus for coating same



Jan. 25, 1927.

A coATED come AND METHOD oF AND APPARATUS FOR coATING SAME Patented Jan. 25, 11927.'

UNIT-ED STATES PATENT oFFicE.`

FREDERIC wILsoN WILLARD, or sUMMIT, NEW JERSEY, AssIeNoR To WESTERN ELECTRIC COMPANY, INCORPORATED, or NEW YORK, N. Y., A CoBPoRATIoN or NEW YGRK.

COATED CORE ANDMETIICD or AND APPARATUS ECR CCATING SAME.' l

Application filed September 17, 1925, Serial No. 56,935. Renewed October 2Q, 1926.

'lhis invention relates to a coated Core and a method of and apparatus for producing it. An object of this invention is to produce a core in strand form having a crlmped or 5 uneven coating of pulp which is attached tol the core solely by the intermingling-of tb fibers in the pulp.

Another object of this invention is to simultaneously produce a plurality of cores having crimped or uneven coatings-of pulp y attached thereto solely by the interiningling of the fibers in the pulp.

Briefly, the method consists in depositing pulpous material on a screen or other suitable foraminous member, engaging the' core with the pulpous material so deposited, depositing an additional amount of pulpous material on the core and the foraminous member, removing the core and the pulpous material attached thereto from the foraininous member, removing substantially all of the moisture from the pulpous material attached to the core, and then wrapping the dried pulpous material on the core to constitute a crimped or uneven coating therefor. When a plurality of cores are coated simultaneously the method consists 'in bringing the cores simultaneously into 4engagement with the foraminous member, depositing pulpous material upon the foraminous member and the cores in Contact therewith, removing the cores and the sheet of pulpous material supported thereby, from the foraininous member, removing substantially all of the moisture from the pulpous material, slitting the pulpous material into a plurality of ribbons individual to the cores, and then forming the dry pulpous ribbons on the cores to constitute crimped or uneven coatings therefor. Ina modified form of the invention the attached ribbons of ulp are -narrow and are not wrapped arounclthe core.

The present method may beemployed to advantage for insulating electrical conductors, but it is to be understood that it is not limited to this purposebut is limited only in so far as defined by the' appended claims. Wherev the method 1s used for insulating electrical conductors, manila, wood, rag, cotton, esparto, jute. hemp and asbestospulps may be employed as the coating material,

I but other materials than those specified may be used without departing from the ,spirit and scope of the present invention.

The word ,pulp as used in the specification and claims is to be understoodas deining and including any cohering fibrous mass whether suspended in a liquid, `moist or substantially dry. l

In the accompanying drawings- Fig. l is a. side elevation of an apparatus by which the method ma be practiced;

Fig. 2 is an enlarge plan view of a portion of the apparatus shown in Fig. 1.;

Fivs. 3 and 4 are enlarged sectional views showing theiformation of the pulp on the cores, as it. leaves the felt associated with the foraminous member and after it has been slit into ribbons individual to the cores, respectively;

'Figs 5 and 6 are enlarged sectional views showing the form of the pulp coating during the forming `operation and after the completion vof such operation, respectively, and

illustrating the formation of the pulp on the core in a modified form of the invention.

It is believed that the steps of the method may be readily understood from al detailed description of the apparatus by which the method may be practiced.

Referring to the drawings in detail in which like reference numerals` designate fragmentary top F ies. 7 and 8 are enlar ed sectional views i similar parts throughoutvthe several views,

the apparatuscomprises a drum 10 'which is partially submerged in a liquid containing pulp disposedl Within a trough 11. Y The drum 10 comprises apair of metal sides and a peripheral portion 12 secured thereto.

The periphery '12 is provided with a plu` rality of relatively large perforations 13 which are covered with a sheet of fine wire mesh- 14. *The drum 10 has a centrally-dis? 'posed tubular axle 15 which is rotatably.

mounted in suitable bearings 16 carried by a framework 17 which'supports all of the I elements of the apparatus.

Pulpous material is strained onto the wire mesh 14 as1the drum 10 is rotated in the tank, by maintaining the level of tlilliouid within the drum 10 at a lower level than that of the pulp liquid in the tank 11, as indicated by dotted lines A and B, respecles tively. This dierence lin level is maintained 4by a siphon pipe 18 which hasits 1nlet opening submerged in the liquid withinI the drum and its discharge through the tubular axle 15. The continuous circulation of the pulp liquid is maintained 1n the tank 11 by feeding the pulp liquid fromva supply tank (not shown) into the tank 11 by means of a pipe 19, and out of sald tank through a pipe A20 into a receiving tank (not shown) from which it is pumped back y into Disposed in contact with the wire mesh- 14 is a roll 21 preferably covered with felt and mounted'upon a pair of bracketsl24. rlhe cores to be coated are fed from suitable Supply spools 30, arranged in axial `alignment, over idler rolls 31 and into contact with the pulpous material which has been deposited 'on the foraminous member 14, -as

will be hereinafter described. 'its the drum 10 is rotated the cores are carried into thev liquid containing pulpous material, and when the pulpous material is deposited upon theforaminous member it also covers the cores in contact therewith.

The idler rolls 31 are spacedfrom the periphe 12 of the drum 10 so that the cores are hlrd out of contact with that section of the foraminous member which is near the surface of the liquid in the tank whereby pulp is strained onto said section before the cores are brought into contact therewith. The first deposit of pulp on the foraminous member is indicated by the letterC, while as the drum rotates in the tank. additional amounts of pulpous material are deposited on the cores and the associated foraminous member forming a thicker coating indicated by the letter D. The drum 10 lis rotated in the direction indicated by the arrow (Fig. 1), and the pulp on the -forarninous member, together with vthe associated cores, are

'brought intovcontact with the felt covered roll 21. The periphery of this roll has a :Eoraminous ortion formed of fine wire mesh and when the pulp on the foraminous portion of the drum is brought into contact therewith the free iiquid, so to speak, in the pulp mixture is squeezed out, partially through the foraminous portion of the drum 10 and partially throughthe felt and the as-l sociated foraminous portion of the rollv 21. The partially dried pulp adheres to the felt in sheet form with the cores included therein.

The cores then pass partially around the felt covered roll 21 which serves to remove the deposited material from the oraminous member 14. A roll 23 provided with suitable tension means to press it against the felt roll pulp together and to the coresfas shown i ig. 3. Y i

From the roll 23, the cores with their associated sheet of pulp are passed between a pair of squeeze rolls 40 which serve to remove additional moisture from the pulpous ribbon and force the fibers thereof into more intimate contact. The cores with the partially dried pulp are then passed through a drying chamber 41 into which hot air is introduced through a pipe 42 terminating in a plurality of nozzles 43 disposed within thechamber 41. This step of the improved method.` serves to remove substantially all of the remaining moisture from the pulpous ribbon. L

When a plurality of cores are being coated simultaneously, the attached sheet of pulp, after leaving the drying chamber 41, 1s subjected to the action of a cutter' in the form of a slitting disk 28 bearing upon the periphery of a vdrum 26 whereby the sheet of pulp is split into ribbons individual to the cores. Each core and its associated ribbonof pulp tends to remain in close contact, the cores'being disposed substantially in the center of the ribbons, as shown in F ig. 4. `After leavingthe slittingdisk 28 the cores with their attached ribbons of Vpulp are drawn over guide rolls 32 through forming mechanisms 33 and 34 which wrap the projecting edges of the pulp ribbon around the core and around each other, The appear ance' of thecoatings as they are first acted upon bythe forming mechanisms is illustrated in Fig. 5. Due to substantially all ot' the moisture being removed from the pulp coating before it is subjected to the action of the forming mechanism, the appearance of the exterior' surface of the coating after it leaves the forming mechanism will be crimped or uneven, as illustrated in Fig.

- Such `a coating is particularly suitable for insulating electrical conductors which are to be assembled into cables used for carrying signallingor telephonie currents, especially where'it is desirable that there should be a plurality of air spaces between the conductors when assembled lto form the cable so as to reduce' the electrostatic capacity thereof. It is obvious that the contour of the coatings, as illustrated in Fig. 6, will preventclose nesting `of the conductors when assembled to form a cable,the`reby maintaining the cop-v per density of such cables within the required limlt.

Each of the formers 33 and 34 may comprise essentially two plates which are 1o tated around the core and serve -to wrap the projecting edges of the pulp ribbon there lill around in much the same mantienes' though the core and' pulp ribbon Awere rolledona table top with the palm ofthe hand. The formers 33 and 34 shown in the drawings are identical to that Vfully described in thecopending'application of'H. G. Walker and A! f T. March,'Serial No. 54K ,923, filed March 29,' 1922, and for a detailed description of this mechanism reference is made to the appli-v cation above referredto. From the forming mechanisms the coated cores are stored'onsuitable lcake-up spools 37 and38. In a modified form of the invention, the pulpous ribbon attached to the core -is made narrow and is, notv polished or otherwise wrapped around the core. When simultane-' ously coating a plurality of cores in accordyance with this embodiment of the invention Y unfinished paper in a wet state to the core,v completing the fabrication ofthe paper-.onfy the core. and then wrapping `Athe paper' the'core to constitute a coating there- *around- 4 l for. i v

the cores are'spaced closer to each other', asy illustrated in Fig. 7, and after the attached sheet of pulp has been thoroughly-dried and4 the fibers thereof thoroughly interiningled,` it is subjected to the action of azslitting mechanism which slits the sheet'v of pullp longitudinally, intermediate the cores, as i lustrated in Fig.- 8.

The a paratus two cores in strand form, but` it is to be understood that the machine can be modled .andthe parts duplicated to simultanef ously coata larger number of lcores' without departing from the spirit and scope ofthe present invention.

What is claimed is: 'v l. The method of coa-ting a core in strand form, consisting in subjecting the core t0 a i liquid containing pulp insuch manner that into a rib on disposed longitudinall of the l core, removing substantially all of t e moisture from the pulp and then wrapping the pulp ribbon around'the core to constitute a coating therefor which is retained on the 55 core by an intermingling of the fibers inthe' ul v .A p 3l) The method 'of coating a core .in strandform, which consists in applying a strip-of 4:.v The method of simultaneously coatin a pluralityof cores, which consists in taneoi'islyv subjecting the cores to `a liquidi,

illustrated and .above des scribed 1s adapted to simultaneously coat on disposed longitudinall of the dividual to the cores.

"causing Ua relatiyeA movement 'liquid and the -core whereb pulp is de- 'posited on the core, means-y or drying the containingv pulpl in such manner that pulp is applied thereto, forming said pulp into a intermingling of the fibers in the pulp, removing substantially all of the' moisture from said pulp and then separating the pulp into ribbons individual to the cores. I 5. Themethod of simultaneously coating aplurality of cores in strand form, which consists inj simultaneously subjecting the cores to a liquid v-containingpulp in such manner thatpulp is' applied thereto, 'formf `sheet which'is attached tothe cores by an h ing thepulp into asheet which is attached -to the cores by 'an intermingling of the fibers in the pulp, removing substantially all f 'the liquid from saidpulp, separating the sheet of pulp into ribbons individualtothe cores, and then wrapping the pulp ribbons around vthe individual cores to produce coatingstherefor havin 4 6. The method o simultaneously 'coating a plurality of cores in strand form, consisting in applying a sheet of unfinished paper uneven outer surfaces.

to the cores, completing the fabrication of the paper on the cores,`s eparating the paper longitudinally into strips individual toy the cores, and then wra ping the strips of paper around lthe indivi ual cores to constitute coatings therefor.

7.v The method of coatin a core iny strand form,con`sisting in centra y positioning the core longitudinally in contact with a strip of unfinished --paper in'p.l Wet' state, comwv pleting 'the fabrication of the paper on the core, and then wrapping the edges of the paper'laterally around the lcore to constitute a crimped coating therefor.

8; The method `of simultaneously coating a plurality of cores in strand form,v with pu which consists in depositing wet pulpous material on a"foraminous member, engaging the cores with the pulpous material so deposited, depositing additional pulpous vmaterial upon Athe cores and the foraminous member, removing the cores and the deosited material from the fora-minous memer, applying vpressure -to the material in such manne'1- that it is caused to adhere t0 the cores bya-feltin'g of the pulp fibers, re-

.moving substantially all of the moisture frointhe pulpousfmaterial, and then se arating thepulpous material'into ribbons 1n- 9.*In a 4machines for coating a core' inf strand form with pulp, a, receptacle4 for holding a liquid containing pulp., means for,

. etween the deposited pulp, a wrapping mechanism', and

10. vIn a mac ine for simultaneously coatmeans for subjecting tlief'core with itsidried p'ul vto saidwrapping mechanism' whereby jsai pulp 'is-wrapped around the core toconstitute a coatin therefor.'l 13o' ing a plurality of coresl with pulp, a -receptacle for holding Aa li uid containing pulp, means for causing a re ative movement between the liquid and the cores whereby a sheet of pulp is attached thereto, means for removing substantially all of the -I'noisture from the attached sheet of pulp,'and means for slitting the dried sheet of pulp into ribbons individual to the cores to constitute coatings therefor having uneven exterior surfaces.

11. In amachine for simultaneously coattacle for holding a liquid containing pulp,

- means for causing a relative movement between theliquid and the cores whereby .a sheet of pulp is attached thereto, means for removing substantially all of the ,moisture from the attached sheet of pulp, ,means for slitting the dried pul into ribbons individual to the cores, and means forforming the individual ribbons around the cores to constitute coatings' therefor.

12.' In a machine for simultaneously coat- 13. An electrical conductor, comprising a.

metallic, strand and an integral continuous `flexible coating consisting of loosely elted pulp attached to the strand in a wet condition and wrapped therearound in state. y

14. An electrical conductor comprising a metallicstrand and an integral continuous flexible coating having a contour different than that of the core, the said coating consisting of loosely felted pulp j attached lto the core in a Wet state and Wrapped around the core when in a dry state.

Irl-Witness whereof, I hereunto subscribe my name this 4th day of September A. D., 1925. l

FREDERIC WILSON WiLLARD.

a dry. 

